Jenson Button's McLaren topped the second day of pre-season Formula 1 testing at Jerez, as the Mercedes-engined teams demonstrated an early advantage in 2014.

Button topped the official wet-weather running in the morning, despite the MP4-29 not having appeared at all on day one in Spain. The track dried after midday and drivers switched to slick rubber. Button then swapped fastest laps with the Force India of former teammate Sergio Perez.

The Renault-engined teams struggled with a suspected energy store issue. Caterham's Ericsson managed the most laps with 11, but his best was nearly 14 seconds slower than Button.

Red Bull gave up running altogether after Sebastian Vettel had managed a handful of laps early on, while Toro Rosso failed to make it out at all.